A little more info as to how/why this happened ? When did this happen ? Was it fine one day and then the next day it wouldn't boot or has then been an issue that has gotten worst over time ?
On the laptop try the following
Boot the laptop up and PRESS F8.....boot into Safe Mode Go to START>ALL PRGRAMS>ACCESSORIES>SYSTEM TOOLS> SYSTEM RESTORE
Restore it back to a day that you know it worked....once it reboots see if you can get in and run a Virus Scan and Spyware scan....
If you can't get in via SAFE MODE then your screwed !
As for the Desktop and internet issue ? What error are you getting ? Did this happen at the same time the laptop stopped working ?